icuSources/common/unicode/ustringtrie.h

   1 /*
   2 *******************************************************************************
   3 *   Copyright (C) 2010-2012, International Business Machines
   4 *   Corporation and others.  All Rights Reserved.
   5 *******************************************************************************
   6 *   file name:  udicttrie.h
   7 *   encoding:   US-ASCII
   8 *   tab size:   8 (not used)
   9 *   indentation:4
  10 *
  11 *   created on: 2010dec17
  12 *   created by: Markus W. Scherer
  13 */
  14
  15 #ifndef __USTRINGTRIE_H__
  16 #define __USTRINGTRIE_H__
  17
  18 /**
  19  * \file
  20  * \brief C API: Helper definitions for dictionary trie APIs.
  21  */
  22
  23 #include "unicode/utypes.h"
  24
  25
  26 /**
  27  * Return values for BytesTrie::next(), UCharsTrie::next() and similar methods.
  28  * @see USTRINGTRIE_MATCHES
  29  * @see USTRINGTRIE_HAS_VALUE
  30  * @see USTRINGTRIE_HAS_NEXT
  31  * @stable ICU 4.8
  32  */
  33 enum UStringTrieResult {
  34     /**
  35      * The input unit(s) did not continue a matching string.
  36      * Once current()/next() return USTRINGTRIE_NO_MATCH,
  37      * all further calls to current()/next() will also return USTRINGTRIE_NO_MATCH,
  38      * until the trie is reset to its original state or to a saved state.
  39      * @stable ICU 4.8
  40      */
  41     USTRINGTRIE_NO_MATCH,
  42     /**
  43      * The input unit(s) continued a matching string
  44      * but there is no value for the string so far.
  45      * (It is a prefix of a longer string.)
  46      * @stable ICU 4.8
  47      */
  48     USTRINGTRIE_NO_VALUE,
  49     /**
  50      * The input unit(s) continued a matching string
  51      * and there is a value for the string so far.
  52      * This value will be returned by getValue().
  53      * No further input byte/unit can continue a matching string.
  54      * @stable ICU 4.8
  55      */
  56     USTRINGTRIE_FINAL_VALUE,
  57     /**
  58      * The input unit(s) continued a matching string
  59      * and there is a value for the string so far.
  60      * This value will be returned by getValue().
  61      * Another input byte/unit can continue a matching string.
  62      * @stable ICU 4.8
  63      */
  64     USTRINGTRIE_INTERMEDIATE_VALUE
  65 };
  66
  67 /**
  68  * Same as (result!=USTRINGTRIE_NO_MATCH).
  69  * @param result A result from BytesTrie::first(), UCharsTrie::next() etc.
  70  * @return true if the input bytes/units so far are part of a matching string/byte sequence.
  71  * @stable ICU 4.8
  72  */
  73 #define USTRINGTRIE_MATCHES(result) ((result)!=USTRINGTRIE_NO_MATCH)
  74
  75 /**
  76  * Equivalent to (result==USTRINGTRIE_INTERMEDIATE_VALUE || result==USTRINGTRIE_FINAL_VALUE) but
  77  * this macro evaluates result exactly once.
  78  * @param result A result from BytesTrie::first(), UCharsTrie::next() etc.
  79  * @return true if there is a value for the input bytes/units so far.
  80  * @see BytesTrie::getValue
  81  * @see UCharsTrie::getValue
  82  * @stable ICU 4.8
  83  */
  84 #define USTRINGTRIE_HAS_VALUE(result) ((result)>=USTRINGTRIE_FINAL_VALUE)
  85
  86 /**
  87  * Equivalent to (result==USTRINGTRIE_NO_VALUE || result==USTRINGTRIE_INTERMEDIATE_VALUE) but
  88  * this macro evaluates result exactly once.
  89  * @param result A result from BytesTrie::first(), UCharsTrie::next() etc.
  90  * @return true if another input byte/unit can continue a matching string.
  91  * @stable ICU 4.8
  92  */
  93 #define USTRINGTRIE_HAS_NEXT(result) ((result)&1)
  94
  95 #endif  /* __USTRINGTRIE_H__ */